1. V. L. Bonch-Bruevich, and V. D. Iskra, in Proceedings of the 6th International Conference on Amorphous and Liquid Semiconductors (Leningrad, 1975), p. 182.
2. V. L. Bonch-Bruevich, and V. D. Iskra, Sov. Phys. Semicond. 23, 385 (1989).
3. I. Kneppo and J. Cervenak, Solid State Electron. 15, 587 (1972).
4. P. K. C. Pillai, and R. Nath, Phys. Status Solidi A 37, 491 (1976).
5. Electronic Phenomena in Glassy Chalcogenide Semiconductors, Ed. by K. D. Tsendin (Nauka, St.-Peterburg, 1996) [in Russian].